1. Field
This disclosure relates generally to semiconductor packaging, and more specifically, to incorporating a capped semiconductor device in a package having interconnected components.
2. Related Art
In an ever-increasing number of devices, including consumer devices and medical devices, it is becoming desirable to incorporate a greater variety of micro-electromechanical sensor (MEMS) devices for added usability and functionality. MEMS devices are small integrated devices that combine electrical and mechanical components, ranging in size from a sub micron level to millimeter level. Examples of MEMS devices include accelerometers, inertial sensors, micro actuators, pressure and flow sensors. Semiconductor MEMS devices are typically formed on a substrate and then protected with a cap, which makes a MEMS device relatively thick as compared to other semiconductor devices.
MEMS devices can be protected in a package for incorporating the MEMS device into a system. Traditionally, a MEMS device is encapsulated separately into a QFN or other type of package, and then coupled to a processor or ASIC via a printed circuit board. A drawback of this method of combining a MEMS device with a processor externally is that such a configuration can be physically larger than is ideal or allowable for some applications. Another typical method for incorporating a MEMS device into a system is to stack the MEMS device with a processor or ASIC and then encapsulate the stack as a package. A drawback of this method of combining a MEMS device with a processor is the thickness of the encapsulated stack may be physically larger than some applications may allow.
It is therefore desirable to provide a thin package combining a MEMS device with a processor or ASIC for space-constrained system-in-package applications. One issue to overcome in providing such a package is that electrical contacts for a MEMS device are typically located on a top surface of the substrate in a region of the substrate not protected by the cap. In certain packaging technologies (e.g., redistributed chip packaging and fan out-wafer level packaging), this removes the MEMS device contacts from a region typically used for interconnect purposes. Therefore, a way must be found to electrically couple the MEMS device contacts with contacts for the incorporated processor or ASIC.
The use of the same reference symbols in different drawings indicates identical items unless otherwise noted. The figures are not necessarily drawn to scale.